Men Who Work Out Have Superior Sperm

A simple change in lifestyle may be all some guys need to get their swimmers back in shape.

Scientists estimate that approximately 1 in 20 men in North America are infertile, or unable to father children. Male infertility, however, can take many different forms: Some guys are infertile because they don't release any semen when they ejaculate, either because of a blockage in their reproductive tract or an improperly functioning set of valves. More often, though, infertile guys can ejaculate just fine, but they have an issue with the quantity or quality of the sperm they're releasing.

No matter what form it takes, infertility is highly distressing to men. Among other things, it has been linked to low self-esteem and feelings of anxiety.

Fortunately, however, we aren't dealing with a hopeless situation here—and it turns out that there may even be an easy fix for it, at least for the guys with low sperm counts. Believe it or not, many of these same men may actually be able to restore their fertility entirely on their own, without the need for medical treatment or expensive—and unproven—fertility-boosting supplements. For guys who are otherwise healthy and don't have testicular problems, a simple change in lifestyle may be all they need to get their swimmers back in shape.

First, let's clear up a common myth about what causes low sperm counts: It is not—I repeat, not—the result of wearing tighty whities. A study published last year in The Journal of Sexual Medicine found that the type of underwear heterosexual men wear (boxers or briefs) wasn't related to fertility status or the length of time it took their female partners to become pregnant.

In other words, Fruit of the Loom isn't to blame when guys have low sperm counts. Far more important than a man's undergarment of choice is how well he takes care of himself physically. Indeed, several studies have emerged indicating that exercise, in particular, can have a dramatic effect on the quality of a man's semen.

In a 2011 study published in Reproductive Health, a group of obese men between the ages of 20 and 59 took part in a 14-week weight-loss program. Before the program began and after it ended, each man provided semen samples for researchers to analyze.

At the start of the study, the more overweight men were, the worse the quality of their semen. However, the more weight men lost over time, the more their semen quality improved. In fact, weight loss was linked to an increase in the number of sperm released, as well as an overall improvement in sperm health.

Building on these results, a new paper published in the journal Cytokine describes the results of a randomized controlled experiment in which infertile men aged 20 to 45 who were living a sedentary lifestyle were either instructed to start getting moderate aerobic exercise for 24 weeks or not. All of these men were patients at an infertility clinic and had been having infertility issues for a year or longer.

Researchers found that exercise was linked not only to improvement in sperm quality, but also to increased odds of their partners becoming pregnant. In other words, a few months of moderate exercise actually demonstrated the ability to reverse male infertility.

One caveat to these studies is that it doesn't seem to be the case that all exercise is equal when it comes to the health of men's sperm—in fact, certain exercises may be counterproductive. A 2015 study published in the Clinical Journal of Sport Medicine found that non-professional male cyclists who began biking at least 12 hours per week for 16 weeks experienced not just a drop in their sperm counts, but also a decrease in the quality of the sperm they produced.

Even after a 30-day recovery period at the end of the study, cyclists' sperm quantity and quality remained low. In other words, if you and your partner are hoping to get pregnant in the near future, maybe take it easy on the biking.

Beyond getting moderate exercise, changing other aspects of your lifestyle may also help improve the health of your sperm. Specifically, you might want to cut back on your smoking and drinking, as well as your coffee and soda habits in light of research finding that high levels of tobacco, alcohol, and caffeine consumption are linked to lower quality semen.

Of course, none of the above are guaranteed fixes for a low sperm count. And if you're in good physical shape and still experiencing fertility issues, it's definitely worth a trip to the doctor to figure out what's going on.

The bottom line, though, is that if you're worried about the health of your sperm, there's no need to waste your money on new undies. Instead, research suggests that you'd probably be much better served by using that money to join a gym—and maybe cutting back on a few of your vices, too.

Justin Lehmiller is the director of the social psychology program at Ball State University, a faculty affiliate of The Kinsey Institute, and author of the blog Sex and Psychology. Follow him on Twitter @JustinLehmiller.